Yellow monoazo dyestuffs fast to light and process of preparing them



r -ma Feb. 5, 1929.

a UNITED STATES 1,1012 8 PATENT OFFICE.

nnmim WAGNER, or BAD sonnn ox-m mms, m mmononius vossim,

or HOGHST-ON-IEE-IAIN, enmumr, nsslenons 'ro eussnnm mmsrm con,- roiwrron, ornnw Yonx, 1w. 2., A comm-non or nmwnnn. i

innnow moizonzo DYESTUFFS rns'r 'ro uen'r'm rnocnss or rmmme rm.

Our present'invention relates to yellow monoazo dyestuffs fast to light and process of preparing them.

We have found yellow monoazo dyestuflf's of particularly good fastness to light are obtained by. diazotizing the 2.5.6-trichloro-3-amino-1-methylbenzene-4-sulfonic acid and coupling it with compounds of the following formula wherein X stands for a phenylene groupwhose hydrogen atoms are substituted or not,

. and R for the groups alkyl', carboxyl, or carboxyl ester, such as'for instance l-sul'fophenyl-3-methyl-5-pyr'azolone, or l-sulfophen l- 5.-pyrazolone 3-carboxylic acid, or l-sul ophenyl-5-pyrazolone 3-carboxyl1c acid ester or 1- (ii-sulfo-G-chloro) -phenyl 3 meth l 5 O pyrazolone or the like. The 2.5.6-trich ore C 3-amino 1 math lbenzene 4; sulfonic acid can be prepared y chlorinating vpara-tolu enesulfonic acid,- ortha-chlorotoluene-para-' sulfonic acid or 2.6-dichloroto1uene,4-sulfonic acid until these compounds have attained the weight of a trichloro compound, and then nitrating and reducing the product so obtained, as morejfully describe in our copending application Serial No; 212,850, filed August 13, 1927. For, example, 27,55 parts of 1- math l-2.5;6-trichlorobenzene-4-sulfonic acid are olved at 70 C. in 85,5 parts of'suL' furic acid of 97% strength. lntothe solution so prepared 10,25 parts ofvnitric acid of 62% strength are caused to run' at 70 C. inthe course of 3 hours; The-whole is-stirred for 5 hours at 70 0., the nitro-sulfonic acid -which has formed is separated in known mannor from the sulfuric acid and then reduced to the amino compound as usual; The dye stufis obtainable according to our-present invention are distinguished by an excellent fastnew to light and are in this respect b far suow dyepath of 2.5.6-tri'ch1oro-3-amino-1 that valuable, very pure,

. NlTeclaim; v I

process of preparin yellow monand fast 1 methyl-benzenei-sulfonic acid are dissolved together with 40. parts of caustic soda in 10000 parts of water. To this'solution are added 70 parts of sodium nitrite, and the solution so prepared is caused to run into a mixture of parts of ice with 350 parts of hydrochloric acid of 22 B. The whole is then stirred for one hour. The diazo solution thus No Drawing. Application filefhugust 18, 1987, Serial No. 312,849 and lnflermany August 19, 1926. I

obtained is introduced into a solution, cooled to.0 C. to'5 0., prepared of 288,5 parts of 1- o zolone, 250 parts of sodium carbonate and 5000 parts of water.. The mass is further stirred for 8 hours and the roduct of the re action is thensalted out, tered and dried. The d estufl thus obtained dyes wool a pure ye ow shade of excellent fastness to water, sodium'carbonate and hotpressing, 1

and ofan eminently 00d fastness to light.

It correspondsprobab y to the formula: s'omm on Y 1. The 02:20 dyestufls fast to light by. iazotizing the 2.5.6 trichloro-3 amino '1-- methylbenzene 4-sulfonic acid and con ling it with acompound of the following ormula: m on. n g

c 4, I liia iwx soaon g and R for the carbonyl, orcar--.

boxyl ester.

2., The process of 25.6 trichloro-3 amino 1 {methylbenzene re yellow mon- I oazo dy fast to by the 1M 4-su1fonic acid and coupling it with a compound of the following ormula:

wherein X stands for a phenylene group whose hydrogen atoms are substituted or not,

and R for the groups methyl, carboxyl, or

carboxyl ester.

3. The process of preparing yellow monoazo dyestuffs fast to light by diazotizing the 2.5.6 trichlorofB amino 1 methylbenzene -sulfonic acid and coupling it with a compound of the following formula:

H OH.

l I n x -sozon L=N wherein X stands for a phenylene group whose hydrogen atoms are substitutedor not.

4. The process of preparing a yellow monoazo dyestuif fast to light by diazotizing the l 2.5.6 trichloro-3 amino 1 methylbenzene 4-sulfonic acid and coupling it with thecompound of the following formula:

. 5. As new products, monoazo dyestuffs of the following formula soioNa' OH 01 I 3\--N-N o v N- x-soloma 01 9 1' Ha {I wherein X stands for a phenylene group whose hydrogen atoms are substituted or not and R for the groupsalkyl, carboxyl or carboxyl ester, the said dyestuffs yielding yellow I dyeings of excellent fastness to light.

6. As new products,- monoazodyestufi's of the following formulaz 1 wherein X stands whose hydrogen .atoms are substltutedor not for a phenylene group.

and R for the groups methyl, carboxyl'or carboxyl ester, the said dyestufls yielding yellow dyeings of excellent fastness to light. 7. As new products, monoazo dyestuffs of wherein X stands for a phenylen'e group whose hydrogen atomsare substituted or'not,

the said dyestuffs yielding yellow dyeingsof excellent fastn'ess to light.

-' 8. As a new product, the monoazo dyestufi of the following formula:

S OzONa OH dyeing Wool a pure yellow tint of excellent fastness to water, sodium carbonate and hot pressing, and of an eminently good fastness to light. I

In testimony whereof, we aflix oursignatures.

HERMANN W AGNER. 'BARTHOLOMAUS I VOSSEN. 

